A Cease-Fire in Yemen, but Fighting Is Persistent

SANA, Yemen — A precarious cease-fire took effect in parts of Yemen on Tuesday night, in the first negotiated halt to hostilities since Saudi Arabia started a bombing campaign against Yemen’s Houthi rebels in late March.

There were reports of clashes and at least one airstrike in the southern city of Aden, a major confrontation point in Yemen’s war, after 11 p.m., the starting time for the cease-fire. And vicious fighting in the hours leading up to the truce, including airstrikes that were reported to have killed at least 70 people, cast doubt on the willingness of the combatants to abide by terms of the cease-fire, which is supposed to last for five days.

More than 1,400 people, mostly civilians, have been killed in Yemen since a Saudi-led military coalition began its military intervention in order to thwart territorial advances by the Houthis and their allies. International relief agencies had pleaded for a pause in the fighting to deliver fuel, food and other supplies to Yemen, a deeply impoverished country that has been effectively quarantined for seven weeks by a Saudi-led naval and air blockade.

The Saudis, who had faced growing criticism for the blockade, as well as for airstrikes that had killed civilians, proposed the truce last week and said the five-day cease-fire could be extended. The Houthis accepted on Sunday.

Sana, the capital, which had been struck by nightly bombings for weeks, went quiet on Tuesday about half an hour before the deadline. A resident in the city of Taiz, where fighting had raged, said late Tuesday that the clashes had subsided as the cease-fire had taken hold, but restarted a few hours later.

There has been little evidence so far of a broader political breakthrough. The intense violence leading up to the cease-fire suggested both the Houthi-led forces and the Saudis had unfulfilled military goals.

The Houthis, who control Sana, have fought for weeks to dominate Aden, seeing it as possible leverage in any future negotiations. They are also trying to prevent Aden from becoming a beachhead for Yemen’s exiled president, Abdu Rabbu Mansour Hadi, whom the Saudis say they will restore as Yemen’s leader.

The Houthi advance against local militia fighters has killed hundreds of people and left large parts of Aden in ruins. The Houthis are allied with the security forces loyal to Yemen’s previous president, Ali Abdullah Saleh.

Thwarted in their attempts to stop the Houthis, the Saudis intensified their bombing on Monday and early Tuesday. They struck a number of targets in Sana, including what residents said was a weapons and ammunition depot on a mountain overlooking the city, causing an enormous explosion. Ordnance hurled from the depot by the blast sent shrapnel crashing into homes, witnesses said.

Local health officials and the Interior Ministry said at least 57 people had been killed, in one of the highest death tolls from airstrikes since the conflict began.

Other airstrikes, on a market outside the port of Hodeida, killed at least 20 people, local health officials said. The Saudi-led coalition also bombed a prison in northern Yemen, killing at least 30 inmates, according to residents.

Further complicating the prospects for the cease-fire, an Iranian cargo vessel that Iran said was laden with emergency relief supplies was headed toward Yemen on Tuesday, setting up a potential confrontation with Saudi Arabia.

Iran, which is allied with the Houthis, had previously sent a plane toward Sana carrying what it said were relief supplies to the Houthis. In response, the Saudi-led coalition bombed the airport in the Yemeni capital, forcing the Iranian plane to turn back.

Iranian news agencies said on Tuesday that the cargo vessel, flying the Red Crescent Society of Iran flag, was escorted by Iranian naval warships as it set a course from Iran for Hodeida.

The United Nations refugee agency said Tuesday that one of its ships managed to reach Hodeida on Friday, despite the blockade, and was preparing to “significantly step up its assistance” once the cease-fire took effect.